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rohitr
Posts: 2
Registered: ‎04-27-2011
Accepted Solution

TIME TO COMPLETE COOLING ANALYSIS

1061 Views, 16 Replies
08-17-2011 02:22 AM

Hello all,

 

I have a problem regarding time to complete cooling analysis.I am analysing simple component with about 65000 elements.

I have analyse the component using fil+flow+warp sequence.To complete the same analysis it hardly takes 4 to 5 hours.

 

now wish to analyse the component using cool+fill+flow+warp. but cooling anaysis take longer time to complete near about 18 hours or more.

The cooling circuit is simple without any defects.

Kindly let me know suggetions

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Employee
yannick.moret
Posts: 115
Registered: ‎04-28-2009

Re: TIME TO COMPLETE COOLING ANALYSIS

08-17-2011 03:43 AM in reply to: rohitr

Use a machine with enough RAM.

Cool need to write some matrix to solve the thermal solution.

If there is enough space in RAM, it will put it all in RAM, and analysis time will be fast.

If you don't have enoug RAM, it will put it on your hard disk, and then the time will be long as the CPU will have to get the data from it.

It is easy to check, if you look in task manager and see cool is not using 1 core full time, that mean it is runningon disk and will be pretty slow.

 

Look at start of screen output in cool :

Total Mbytes required for Cool analysis = 3628.13

Total Mbytes available for Cool analysis = 420143.38

Now beginning the task: Input part model

Current time is: Thu Aug 11 15:41:52 2011

 

So for example here I need 3.6 gig of memory.

 

Think at closing synergy to save some RAM also while your analysis is running, if you are a bit short on your machine.

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Valued Contributor
abakharev
Posts: 62
Registered: ‎08-25-2008

Re: TIME TO COMPLETE COOLING ANALYSIS

08-17-2011 08:44 PM in reply to: rohitr

Is it steady-state cool or transient?

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New Member
tobi_cologne
Posts: 2
Registered: ‎08-19-2011

Re: TIME TO COMPLETE COOLING ANALYSIS

08-19-2011 05:57 AM in reply to: abakharev

Hello!

 

I have no solution, but the same problem. I'm using a 12 gb machine so I think it has to be enough. I even have the problem with just filling analysis, it takes really much time (10 hours for dual domain model). When the analysis has completed, the message window "Analysis complete" appaers 10 or nearly 15 times, which I have to click "OK". I just installed AMI 2012 on my machine (OS: VIsta).

 

Okay thanks for your replies! :-)

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Board Manager
raalteh
Posts: 254
Registered: ‎04-14-2009

Re: TIME TO COMPLETE COOLING ANALYSIS

08-19-2011 01:34 PM in reply to: rohitr

When you part has a lot of details and small elements, the Cool solver with boundary element method may get slowed down. If you are using a 3D mesh, and you are using Moldflow Insight 2012, try the new Transient Cooling capabilities (even while using it for a steady state analysis). This is likely going to converge much quicker. 

Hanno van Raalte,

Product Manager for Autodesk Simulation Moldflow products
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Contributor
piotr.wozniacki
Posts: 25
Registered: ‎07-20-2011

Re: TIME TO COMPLETE COOLING ANALYSIS

08-21-2011 04:27 AM in reply to: raalteh

I have a very fast computer with 16GB RAM, and yet the second phase of Cool (FEM) 3D anaysis does take enormous emount of time to complete.

 

Even though the entire sequence is parallelized, and I check the option for using max number of threads - and all 8 threads are reported to be in use - only  the first phase of the Cool (FEM) 3D snalysis can tax my fasy i7 extreme CPU up to 100% for all 8 threads. The second phase - transient within cycle - only uses some 15-18% - and this is not due to low memory and swap file trashing!

 

Just why is that, and what's the bottleneck?

 

Piotr

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New Member
rohitr
Posts: 2
Registered: ‎04-27-2011

Re: TIME TO COMPLETE COOLING ANALYSIS

08-24-2011 10:15 PM in reply to: abakharev

hello all,

How to define steady state or transient cooling ?

 

Kindly let me know if any suggetions.

 

ROHIT

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Valued Contributor
HugoHerrera7042
Posts: 62
Registered: ‎07-07-2009

Re: TIME TO COMPLETE COOLING ANALYSIS

08-25-2011 09:56 AM in reply to: rohitr

Hi,

happy to find this discussion since i was going to start a very similar one.

 

I have a midplane model with cool+fill+pack+warp (38,000trias elements) PP 32% TF, and when I run the analysis it gets stucked at ~54% of cooling analysis...for days...withouth any error or warning message...now why is that happening??

 

i know in my experience that usually cooling analyses involving fiber filled materials take significantly longer, but i don't think i'm going anywhere with this iteration....anyone has experienced the same thing?? i have run this model in several computers with enough RAM, memory, 64-bit, etc. but still, i have the same problem....

 

i'm using the 2011 version - moldflow insight. (user for ~5years and i have never seen this problem before)

 

i also thought it was a convergency tolerance problem and changed the convergence to 0.5 with no success. i will try and change the geometric influence from ideal to automatic to see if it improves...

 

any help greatly appreciated....i'm attaching my model for your info...

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Contributor
petr_AL
Posts: 17
Registered: ‎02-23-2011

Re: TIME TO COMPLETE COOLING ANALYSIS

08-29-2011 06:44 AM in reply to: rohitr

Hi,

 

we have 3D study, 5mil. tetras, Cool+Fill+Pack+Warp.

Time for Cooling - about 7days. Job manager had show during this week no progress (100%), but at log file

is possible to see increasing number of iteration - see image.

CPU was working on average 10%. Memory about 80% full.

Time for Fill+Pack+Warp - about 2days.

 

Computer: HP Z800, 2x Xeon 2.67MHz (12 cores), 24GB RAM

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Employee
yannick.moret
Posts: 115
Registered: ‎04-28-2009

Re: TIME TO COMPLETE COOLING ANALYSIS

08-29-2011 06:56 AM in reply to: petr_AL

If analysis is taking so long, that is moist likely you don't have enough ram on your machine.

I bet you can see constant access on disk and that the cool process is taking only a few % of the CPU.

in the image you attached the part where it shows the required disk space is missing. That is the key.

 

I pasted below my answer

Cool need to write some matrix to solve the thermal solution.

If there is enough space in RAM, it will put it all in RAM, and analysis time will be fast.

If you don't have enoug RAM, it will put it on your hard disk, and then the time will be long as the CPU will have to get the data from it.

It is easy to check, if you look in task manager and see cool is not using 1 core full time, that mean it is runningon disk and will be pretty slow.

 

Look at start of screen output in cool :

Total Mbytes required for Cool analysis = 3628.13

Total Mbytes available for Cool analysis = 420143.38

Now beginning the task: Input part model

Current time is: Thu Aug 11 15:41:52 2011

 

So for example here I need 3.6 gig of memory.

 

Think at closing synergy to save some RAM also while your analysis is running, if you are a bit short on your machine.



Please use plain text.